An inverter welder for electric arc welding normally includes a rapid switching inverter including a transformer having a primary stage magnetically coupled with the secondary stage that creates an AC or pulsating current. The AC output current is rectified and used in the electric arc welding process. The primary stage of the transformer is a winding which is subject to a series of positive polarity current pulses alternating with a series of negative polarity current pulses. In some inverters, the primary winding is divided into two sections, one receiving the positive polarity pulses and the other receiving the negative polarity pulses so that the secondary stage, or secondary winding, outputs an AC current. This AC current is rectified and filtered to produce a DC welding current. Rapidly created series of positive current pulses and negative current pulses are caused by closing a switch in a series circuit with an input DC link. The switching rate is normally about 20 kHz; however, other super audio frequencies are used. The "switch" may include two or more switches in series so that the switch for the positive polarity pulses and the switch for the negative polarity pulses operate in sequence to create the AC primary current. In this type of power supply for an arc welder, the arc current is sensed at the welding operation and is used as a feedback signal to control the length of time the two switches are closed to control the output welding current at a set current. Such control systems also involve an inner loop for sensing the current in the primary stage of the output transformer to create another feedback parameter which is combined with the arc current to control the two switches driving the primary stage of the transformer. The outer loop current feedback is normally sensed by a shunt in the output circuit. A shunt reads the actual current being used in the welding operation to give an accurate current feedback signal. The inner control loop presents more challenges. The current used in the primary stage of the output transformer must be determined in a real time manner. In the inverter, a shunt can not be used because the pulsating current has a very high frequency and relatively high power. Such factors cause heating of the shunt, as well as causing inaccuracy in the high frequency response of a shunt. Another drawback of a shunt is that it provides no electrical insulation. Consequently, the inner loop feedback control for current in a rapid switching inverter has heretofore used a current transformer responsive to high frequency pulses and capable of handling high current power signals. A current transformer in the primary stage has been suggested due to its high frequency response, high power capability and the ability to isolate the sensed current signal form the input stage of the inverter. The use of a current transformer in certain applications has not been completely successful in obtaining the inner loop component of a current mode control system. As long as the AC current being sensed by the current transformer is symmetrical, there is no net DC component and the current transformer provides a satisfactory feedback signal for the inner loop of the welder. However, if the AC current being measured becomes asymmetrical or unbalanced for any reason, the current transformer tends to saturate and distort the signal. The signal is distorted by adding a DC shift that is proportional to the DC component in the main transformer. This shift is caused by the current transformer's inability to produce an output with a DC component. By adding this DC component the "area" of the positive pulse equals the "area" of the negative pulse and the current transformer's flux is forced to be balanced by resetting itself during the switch off-time. The current signal in the inverter can become asymmetrical when the main transformer to the inverter is pushed into saturation or when the pulses to the main transformer are not equal for each half cycle. In order to prevent an asymmetrical signal from saturating the current transformer used to measure the primary current in the inverter, it is common practice to employ a DC blocking capacitor in combination with the current transformer. The DC blocking capacitor is either used in series with the primary or secondary of the current transformer. Although such a DC blocking capacitor in the secondary of the current transformer will prevent the secondary from causing the transformer to saturate, such capacitor will not prevent an asymmetric primary current from causing a distorted output signal. Consequently, a current transformer in the primary stage of the main transformer to sense the current through the transformer coil often experiences imbalanced current pulses. The positive polarity pulses are different from the negative polarity pulses. The blocking capacitor in the current transformer will eliminate the DC component by shifting the current transformer output signal. Consequently, the current transformer will shift the current pulses to balance the DC component. When the current transformer signal shifts, the current mode control will regulate the pulse width based upon a distorted signal. The control system will continue creating current pulses having different widths which continues the unbalanced process. This unbalance is initially quite small; however, the difference continues to increase causing the output signal of the current transformer to shift further to compensate for the current unbalance. Consequently, the current imbalance or unbalance will continue to increase until the main transformer is pushed into saturation. Running the transformer in saturation causes the switch elements to heat up by being subjected to high currents. Also, a saturated main transformer will reduce the ability to deliver power to the secondary output.